What to Include in a CNC Machining RFQ: Checklist and Template

A complete CNC machining RFQ (Request for Quotation) helps a manufacturer understand your part, estimate production costs, and provide a useful quotation.

Missing information can lead to additional questions, unclear pricing, or unexpected changes after production begins.

Whether you are ordering one prototype or thousands of custom aluminum components, the goal is to make the part requirements clear before requesting a price.

This guide explains what to include in a CNC machining RFQ and provides a copy-ready template for purchasing teams and engineers.

Use this checklist before sending your request.

Not every project requires every document. A simple prototype may need fewer details than a precision component with tight tolerances, special finishing, and formal inspection requirements.

The important thing is to identify every requirement that affects manufacturing, acceptance, cost, or delivery.

A 3D CAD file shows the part's geometry. A 2D engineering drawing communicates many of the dimensions and requirements used to manufacture and inspect it.

For most precision CNC parts, providing both is the clearest approach.

A clean solid model helps the manufacturer understand:

1:Overall shape and dimensions

2:Holes, pockets, slots, and other features

3:Wall thickness and part geometry

4:Areas that may require special tools or multiple setups

STEP/STP is a widely used neutral format for exchanging solid models between different CAD systems.

Other formats, such as IGES or Parasolid, may also be suitable if the supplier supports them. Confirm the required format before submission.

Include the information needed to define the finished part:

1:Datum references and geometric tolerances where needed

2:Thread sizes and depths

3:Material and temper

4:Surface finish and coating requirements

5:Critical dimensions and inspection notes

A 3D model defines the geometry; a clear drawing defines how important features must be measured and accepted.

Make sure the drawing and CAD file represent the same revision. If they conflict, identify which document governs the specification before production.

Our recently published How to Prepare a Drawing for CNC Machining guide explains how to organize dimensions, datums, threads, and revision information.

Avoid vague descriptions such as “aluminum” or “stainless steel” when the exact grade matters.

For example, specify 6061-T6 aluminum instead of simply “aluminum” when that is the required material.

If you are open to alternatives, state the important requirements and ask the supplier to recommend a suitable grade. Do not leave material substitutions unapproved when the application depends on specific mechanical or regulatory properties.

Read our How to Choose CNC Machining Material guide for a practical comparison of materials.

State how many parts you need now, and provide expected repeat or annual demand if known.

For example:

1:Prototype: 5 pieces

2:Initial batch: 100 pieces

3:Potential repeat order: 1,000 pieces

4:hese are illustrative quantities, not a required order structure.

Quantity affects how setup, programming, fixtures, and material purchasing costs are distributed across the order. A process suitable for five prototypes may not be the most economical choice for a larger production batch.

Include your target delivery date and shipping destination. If you have a hard deadline, tell the supplier when the parts must arrive, rather than only stating when they should leave the factory.

Also identify special packaging, labeling, or documentation requirements when applicable.

Two quotations may differ substantially if suppliers assume different tolerances or finishing requirements.

Identify the dimensions that affect fit, alignment, movement, or function.

For example, a bearing seat may require closer control than a non-functional outside dimension. Applying unnecessarily tight tolerances to every feature can increase machining and inspection costs.

Our new CNC Machining Tolerances Guide explains how to select appropriate requirements.

Specify the required surface treatment, such as:

1:As-machined

2:Anodizing

3:Polishing

4:Sandblasting

5:Another agreed coating or finishing process

If dimensional requirements apply after finishing, state that clearly. For example, anodizing can change the dimensions of aluminum bores, external diameters, and threaded features.

Our recent guide, How Anodizing Affects Aluminum Dimensions, explains why finishing must be considered before machining.

For measured surface roughness, see CNC Surface Roughness Ra vs Rz.

Inspection requirements should match the risk and function of the component.

Depending on the project, you may request:

1:Dimensional inspection report

2:CMM report for selected critical features

3:First Article Inspection (FAI)

4:Material certificate

5:Certificate of Conformance

6:Special traceability or testing documentation

Do not automatically request every report for every part. Specify which features need measurement, what documents are required, and whether inspection applies to every piece or a representative sample.

For example, if five hole positions control assembly, identify those features on the drawing and state the required inspection method where necessary.

Imagine Mike, a purchasing engineer at a US automation company, is requesting 100 anodized aluminum mounting plates. His initial email includes a CAD model and material but does not identify the critical hole tolerances or whether a dimensional report is required.

The supplier must then ask follow-up questions or make assumptions. By clarifying the hole requirements and inspection scope in the original RFQ, Mike can receive a quotation that better reflects the actual project.

Agree on acceptance criteria before production starts.

The quoted price depends on more than raw material.

For example, a simple aluminum spacer and a complex aluminum housing may use the same material but require very different machining time.

Likewise, an urgent order with extensive inspection and special finishing may cost more than a standard production order.

To compare suppliers fairly, confirm that each quote includes the same material, tolerances, finishing, inspection, quantity, and delivery scope.

Our recent What Affects the Cost of Custom CNC Machined Parts? guide explains these factors in more detail.

Before sending your request, check for these common problems:

Missing or conflicting files. The CAD model and drawing should use the same part number, units, and revision.

Vague materials. State the exact grade and temper where required.

Unclear tolerances. Identify functional dimensions rather than expecting the supplier to guess which measurements matter.

Missing finishing instructions. Specify the finish and whether critical dimensions apply before or after treatment.

Unclear quantity or delivery. Provide the actual order quantity, target date, and destination.

Unspecified inspection. State which reports, certificates, and acceptance checks are necessary.

These details can reduce unnecessary back-and-forth and help prevent disagreements about what was included in the quotation.

Use the following template for an email or supplier inquiry.

Subject: CNC Machining RFQ – [Part Number] – [Quantity]

Part Information

1:Part name:

2:Part number and revision:

3:2D drawing attached: Yes / No

4:3D CAD file attached: Yes / No

5:Material and grade:

6:Quantity required:

7:Expected repeat or annual volume, if known:

Technical Requirements

1:Critical dimensions and tolerances:

2:Thread and hole requirements:

3:Surface finish or coating:

4:Inspection reports or certifications:

5:Special manufacturing or packaging requirements:

Commercial Requirements

1:Target delivery date:

2:Shipping destination:

3:Packaging instructions:

4:Other project requirements:

Request: Please review the attached files, confirm any missing specifications, and provide a quotation covering the requested manufacturing, finishing, inspection, and delivery scope.

You do not need to know every technical detail before contacting a supplier. If the material or manufacturing process is undecided, state the application's requirements and ask for a technical review. However, the final specification should be confirmed before production.

A good CNC machining RFQ should tell the supplier what to make, how the finished part will be accepted, how many parts are required, and when they are needed.

Prepare the drawing and CAD model, specify material and tolerances, clarify surface finishing and inspection, and provide quantity and delivery information.

The clearer the RFQ, the easier it is to compare quotations on equal terms and avoid preventable production delays.

Need custom CNC-machined aluminum, stainless steel, brass, or other precision components?

Send your 2D drawing, 3D CAD file, material, quantity, critical tolerances, surface finish, inspection requirements, and target delivery date.

Request a Quote

Our team can review your files and project requirements to evaluate a suitable machining and finishing approach.